Skylight/solar water heating apparatus

ABSTRACT

A skylight/solar fluid (e.g. water) heating apparatus and method involve providing a housing adapted for mounting on a building and a light-transmitting outer cover on the housing so that light can enter the housing. A solar fluid heater is disposed in the housing interiorily of the cover in a manner to absorb solar radiation for heating a working fluid thereof and also to allow some light to pass through the housing into the building.

This application claims benefits and priority of provisional applicationSer. No. 60/782,453 filed Mar. 15, 2006, the entire disclosure of whichis incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to skylight/solar fluid heating apparatusadapted for positioning on a roof and/or wall of a building in a mannerthat incident solar radiation is both transmitted through the apparatusinto the accommodating building and also absorbed by solar collectingcomponents and transferred to a working fluid, such as water, forheating.

BACKGROUND OF THE INVENTION

A wide variety of skylight products currently are available for mountingon a roof or wall of a building in order to allow sunlight to passthrough into the interior of the building to provide some naturallighting in the building.

A wide variety of solar water heating devices also are currentlyavailable for mounting on a roof or wall of a building. A typical solarwater heating device includes piping through which water is passed in amanner that solar radiation absorbed by a fin, plate or other absorberof the device is transmitted to the water to heat it. In a typicalservice application, the solar water heating device is plumbed to aconventional electric or natural gas fired water heater in order toprovide supplemental solar heated water thereto to reduce energyconsumption of the water heater.

SUMMARY OF THE INVENTION

The present invention provides in one embodiment a skylight/solar fluidheating apparatus adapted for positioning on a building and includingcomponents arranged in a manner that solar radiation entering theapparatus can be used to heat a working fluid, such as water, and alsocan be passed through the apparatus into the building for interiorlighting purposes.

In an illustrative embodiment, the skylight/solar fluid heatingapparatus comprises a frame or housing adapted for mounting in or on aroof or wall on a building and a light-transmitting outer glazing orcover on the housing so that solar radiation can enter the housing. Asolar fluid heater is disposed on the housing in a manner to collectsolar energy for heating a working fluid and also to allow light to passthrough the housing into the building. For example, the solarcollector(s) typically include a fluid conduit to which thermal energyabsorbed by the collector(s) is transferred to the working fluid in theconduit. Moreover, the solar collector(s) and/or their relation to thehousing define open spaces or paths for light entering the housing topass through the housing into the building. The solar fluid heatertypically includes one or more solar collectors which can be arranged inany type of pattern and/or configuration on the housing to provide suchopen spaces or paths for light to pass into the building. Thermalinsulation and/or glazing can be employed in the housing and/or on theone or more solar collectors to reduce heat transfer losses in operationof the apparatus.

In a particular embodiment of the present invention offered for purposesof illustration and not limitation, a plurality of solar collectors inthe shape of light absorbing, thin metallic fins extend across a firstdimension (e.g. a width dimension) of the housing and are spaced apartfrom one another along a second dimension (e.g. a length dimension) ofthe housing to provide the open spaces or paths through which light canpass into the building. The dimensions of the light absorbing fins andlight-passing open spaces can be selected as desired to provide the dualbenefit of collection of solar energy for heating a working fluid andtransmission of light into a building to provide interior lighting. Thespacing of the fins can be determined by the overall dimensions of thehousing and the number of fins required to meet the design condition ofthe application.

The present invention also envisions a combination of a water heater (orother fluid heater) of a building and a plurality of the skylight/solarwater heating apparatus described above disposed on the building in amanner to provide solar heated water or fluid thereto to reduce energyconsumption. The invention also envisions connector piping or conduitfor interconnecting rows of fluid conduit sections of solar collectorsof adjacent skylight/solar water heating apparatus in a serial fluidflow manner.

Advantages of the present invention will become morse fully apparentfrom the following detailed description taken with the followingdrawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded, perspective view of a skylight/solar fluidheating apparatus pursuant to an illustrative embodiment of theinvention. The optional shade shown in FIG. 4 is omitted from FIG. 1 forconvenience.

FIG. 2 is a perspective view of the assembled skylight/solar fluidheating apparatus of FIG. 1.

FIG. 2A is a perspective view similar to FIG. 2 with the outer glazingor cover removed to illustrate the solar collector fins and open spacestherebetween in more detail.

FIG. 3 is a perspective view of the assembled skylight/solar fluidheating apparatus disposed in a roof on a building.

FIG. 4 is a cross section of the assembled skylight/solar fluid heatingapparatus schematically showing various components for purposes ofillustration of the apparatus.

FIG. 5 is a schematic view of connector piping interconnecting rows offluid conduit sections of solar collector fins of adjacentskylight/solar water heating apparatus in serial fluid flow manneraccording to an embodiment of the invention.

DESCRIPTION OF THE INVENTION

A skylight/solar fluid heating apparatus purusant to the presentinvention is advantageous to provide the dual benefit of collection ofsolar radiation for heating a working fluid and also of transmission ofsunlight into a building to provide interior lighting. Theskylight/solar fluid heating apparatus can be used in connection withany building which can include, but is not limited to, a home,apartment, garage, office, factory, or any other type of building. Forpurposes of illustration and not limitation, a plurality of suchskylight/solar fluid heating apparatus can be disposed on a roof and/orwall on a building in a manner to provide solar heated water to a waterheater of the building while providing interior lighting.

Referring to FIGS. 1-4, an illustrative embodiment of the skylight/solarfluid heating apparatus is shown including a frame or housing H havinglong and short frame sub-assemblies 1, 2 forming a rectangular frame orhousing, although the invention can be practiced using a housing Hhaving any appropriate shape for an intended service application. Forpurposes of illustration an not limitation, the sub-assemblies 1, 2include long and short housing members 1 a, 2 a wherein thesub-assemblies are made of abutted 2×8 wood boards, or any othersuitably sized wood members, having appropropriate dimensions to formthe housing H when assembled. The wood members can be readily fastenedtogether using wood screws, nails, adhesive, and the like to form thehousing. In lieu of natural wood members, the housing members 1 a, 2 acan comprise composite wood/plastic members, fiberglass, plastic, metal,or any other suitable material for the service application involved.

As shown in FIGS. 1-4, the exterior surfaces of the housing H can beclad with aluminum, plastic, or other protective cladding sheet pieces3, 4 to protect the housing members 1 a, 2 a from adverse effects ofweather over a long time period of use of the apparatus. The long andshort cladding pieces 3, 4 can be attached/sealed to the frame orhousing members 1 a, 2 a, an outer light-transmitting cover 5, and eachother with a commercially available window-caulking product that has a50-year guarantee or by any other suitable cladding fastening/sealingsystem. Additional separate roof cladding sheet pieces 3′, 4′ can beprovided to cooperate with the respective cladding sheet pieces 3, 4 torender the skylight/solar fluid heating apparatus weather-proof.Alternately, the cladding sheet pieces 3, 3′; 4, 4′ can be combined in amanner to provide a fewer number of cladding sheet pieces. The interiorand exterior surfaces of the housing members 1 a, 2 a can be painted ortreated in any suitable manner for cosmetic or other reasons.

The housing H is adapted to be mounted in or on a roof and/or wall on abuilding such as by being received and fastened in an opening in theroof or wall of the building in the same or similar manner that aconventional skylight unit is fastened, although the apparatus can bemounted on an exterior surface of the roof or wall with the roof or wallopening located adjacent thereto. Referring to FIG. 4, the long housingmembers 1 a can be fastened to respective adjacent roof rafters R usingnails, screws and the like for purposes of illustration and notlimitation. The terminology skylight/solar fluid heating apparatus asused herein is meant to include mounting of the apparatus not only in oron a building roof, but also mounting in or on a vertical or slopedbuilding sidewall in a manner that may resemble a window or othersidewall structure for receiving solar radiation.

The skylight/solar heating apparatus includes a light-transmitting outerglazing or cover 5 disposed on the frame or housing H so that sunlightcan enter the housing. The glazing or cover 5 can be transparent ortranslucent to incident sunlight to this end. For purposes ofillustration and not limitation, the outer glazing or cover 5 cancomprise a commercially available double-glazed, cellular polycarbonatesheet produced by Polygal Plastics Industires, Ltd. that transmits about70% of incident sunlight, while substantially excluding tansmission ofUV light however. A sheet thickness of ⅝ inch can be used to this endfor purposes of illustration and not limitation.

An optional interior glazing sheet 6 can be provided between the outercover 5 and the solar fluid heater S to further decrease heat loss fromthe apparatus. This interior glazing sheet 6 is optional depending onthe winter temperature values of the location where the skylight/solarfluid heating apparatus is used. For purposes of illustration and notlimitation, the interior glazing sheet 6 can comprise a single pane oftempered glass or any other suitbale glazing sheet.

The edges of the outer glazing or cover 5 and the optional inner glazingsheet 6 reside or rest in grooves 11 that can be notched out of theinterior of the long and short housing members 1 a, 2 a as shown best inFIGS. 1 and 4. A suitable sealant or caulk can be provided in thegrooves 11 if desired.

The solar fluid heater S is disposed on the housing H in a manner tocollect light for solar heating a working fluid and also to allow lightto pass through the housing into the building. As shown in FIGS. 1-4,the solar fluid heater is disposed below the outer glazing or cover 5and optional inner glazing sheet 6 and toward the interior of thebuilding when the apparatus is mounted on a roof of the building.

For purposes of illustration and not limitation, the solar fluid heaterS is shown schematically in FIGS. 1-4 as comprising a plurality of thin,elongated metallic solar collector fins 7 extending across a firstdimension (e.g. width dimension) of the housing H and spaced apart fromone another along a second dimension (e.g. length dimension) of thehousing to provide open spaces SO through which light can pass into thebuilding. Each solar collector fin 7 is made of a heat conductivematerial, such as copper and/or aluminum, and includes a highabsorptivity selective surface facing the outer glazing or cover 5. Thefin selective surface can be coated with a coating material C, FIG. 4,that absorbs a high percentage of incident solar radiation and emits asmall percentage of solar radiation. Each solar collector fin 7typically includes a length of a heat conductive (e.g. copper oraluminum) fluid conduit section 12 a through which water or otherworking fluid is conveyed wherein the fluid conduit section 12 a can beformed integrally with the collector fin 7 or can be attached to thecollector fin. The heat absorbed by each solar collector fin 7 isconducted to the fluid conduit section 12 a, which is attachedmetallurgically (e.g. soldering, brazing, welding, etc.) or otherwise inheat transfer relation to the associated solar collector fin 7 so as toconduct heat to the water or other working fluid in the fluid conduit.The fluid conduit section 12 a, if exposed, can be coated with thecoating material C. It should be noted that FIGS. 1, 2A, and 4illustrate the solar collector fins 7 and their fluid conduit sections12 a in a schematic manner for convenience in showing these components.The solar collector fins used in an illustrative prototype apparatuseach comprised a Sunstrip™ solar fin commercially available from ThermoDynamics Ltd., 44 Borden Avenue, Dartmouth, Nova Scotia, Canada, whereinthe fluid conduit section is metallurgically bonded/clad in thecollector fin. A suitable coating material comprises a high absorptivityselective surface applied to the fins and can comprise a highabsorptivity Anodic/Cobalt™ anodic surface coating provided by ThermoDynamics Ltd. on the solar collector fins used in the prototypeapparatus. Other suitable high absorptivity selective coating materialscan include, but are not limited to, a high absorptivity so-called BlackCrystal™ coating used in the RITH (Roof Integrated Thermosiphon)Technology Development program by Sandia National Laboratories, SOLKOTE™HI/SORB™-II coating available from Solar Energy Corporation (SOLEC), 129Walters Avenue, Ewing, N.J., black chrome coating, or any other suitablehigh absorptivity coating.

An optional foam thermal insulation layer 13 can be attached (e.g. byadhesive) to a undersurface of each solar collector fin 7 that facesaway from the outer glazing or cover 5 toward the interior of thebuilding. This optional insulation layer 13 can decrease heat loss fromthe solar collector fin.

Still further, an optional movable cellular shade C can be mounted onthe housing H below the solar collector fins 7 to close off a portion orall of the housing H to reduce unwanted heat losses and gains from theskylight/solar fluid heating apparatus during operation. Such movablecellular shade C is commercially produced Hunter Douglas Inc. andincludes tracks T that can be mounted by fasteners on the housingmembers 1 a.

Adjacent ends of adjacent fluid conduits 12 a of the solar collectorfins 7 are connected by soldering or other leak-proof connection by aU-shaped fluid conduit section 12 b. The U-shaped fluid conduit sections12 b each have a connector section 12 s and a pair integral leg sections12 l that are received in passages 1 p provided in the long housingmembers la so as to be supported on the housing members 1 a. In FIGS. 1and 2, a series of seven solar collector fins 7 and six copper U-shapedconduit sections 12 b are shown for purposes of illustration and notlimitation. The solar collector fins 7 thereby are fixedly supported viathe fluid conduit sections 12 a, 12 b on the housing. The exterior sidesof the housing members 1 a can be provided with recesses 1 r to receivethe U-shape fluid conduit sections 12 b so that they do not extendbeyond the sides of the housing members 1 a when they are fastened toroof rafters.

The plumbing or piping of the skylight/solar fluid heating apparatusalso includes a fluid inlet conduit 9 and fluid outlet conduit 10. Thefluid inlet conduit 9 is connected by soldering or other leak-proofconnection to the fluid conduit section 12 a of the lowermost solarcollector fin 7 in FIG. 1. The fluid outlet conduit 10 is connected bysoldering or other leak-proof connection to the fluid conduit section 12a of the upperrmost solar collector fin 7 in FIG. 1. The inlet conduit 9in turn is connected to a source of the working fluid. The outletconduit 10 is connected to a user of solar heated fluid. For example, askylight/solar water heating apparatus can be plumbed to a standarddomestic water heater, which can be used as a supplementary system forhot water. The inlet conduit 9 is connected to a water supply pipe orconduit of the building and the outlet conduit 10 is connected to anelectric or natural gas hot water heater HR. The outlet conduit 10 canbe connected directly to the water heater if the water heater is placedabove the skylight/solar heating apparatus. That is, no pump is requireddue to the thermosyphon effect. The benefit of a thermosyphon set up isthat it requires no moving parts. Thermosyphoning causes a natural flowof the water through the water heating system. On the other hand, if theskylight/solar water heating apparatus is placed above the water heater,a pump is required to pump water through the system.

Another embodiment of the present invention involves connecting theskylight/solar fluid heating apparatus of the invention in aclosed-loop, recirculating manner to a heat transfer coil or other heattransfer device (not shown) of a fluid (e.g. water) heater wherein arecirculation pump (not shown) is provided for circulating the workingfluid between the fluid heater and the sklight/solar fluid heatingapparatus. The working fluid can comprise water, a mixture of water andethylene glycol, or any other suitable heat transfer working fluid.

As described above for purposes of illustration, the plurality of thin,elongated metallic solar collector fins 7 are shown spaced apart fromone another along a second dimension (e.g. length dimension) of thehousing H to provide open spaces SO through which light can pass intothe building while the solar collector fins 7/fluid conduits 12 a areheating water or other working fluid. The dimension of each open spacingSO can be varied as desired for a particular service application toprovide the dual benefit of collection of solar radiation for heating aworking fluid and transmission of sunlight into a building to provideinterior lighting. For purposes of illustration and not limitation, whenthe solar collector fins have dimensions of 6 inches×24 inches, the openspacing SO between adjacent solar collector fins 7 can be 1 (one) inchmeasured in the long direction of the housing H. The housing itself canhave an internal width dimension of 24 inches and internal longdimension of 48 inches in this example.

Practice of the present invention is not limited to the type or thearrangement of solar collector fins 7 shown in FIGS. 1-4 and can bepracticed with any type and/or configuration of one or more solarcollector members where the solar collector members and/or theirrelation to the housing define open spaces or paths for light enteringthe housing to pass through the housing into the building. One or moresolar collector members, such as the solar collector fins, pipes, andthe like, can be arranged in any type of pattern and/or configuration onthe housing to provide such open spaces or paths for light to pass intothe building. For example, solar collector fins of the type describedabove and shown in FIG. 1 can be arranged in other than the seriesarrangement shown in FIGS. 1 and 2A. For example, the solar collectorfins can be arranged to form a “picture-frame” border extending aboutthe inner periphery of the housing so as to leave a reactangular,central open space in the housing for light to pass through into thebuilding. Or, one or more solar collector fins can be suspendedcentrally in the housing to provide an open space between the outerperiphery of the solar collector fins and the inner periphery of thehousing that would provide a “picture-frame” lighting pattern into thebuilding by virtue of the relation of the solar collector fin and thehousing. Still further, the solar collector fins can be arranged inseries extending between the short housing members 2 a to providelongitudinal open spaces, rather than between the long housing members 1a to provide lateral open spaces.

Moreover, the invention envisions connecting the fluid conduit sections12 a to the U-shaped fluid conduit sections 12 b in a manner that wouldpermit manual or motor actuated pivoting of the fluid conduit sections12 a and collector fins 7 carried thereon in the housing relative to thefixed U-shaped fluid conduit sections 12 b to vary the open spacing SObetween adjacent collector fins and improve incident solar radiationcollection. For example, a leak-proof rotary connection can be providedto this end between the fluid conduits 12 a and the U-shaped conduits 12b.

The solar fluid heater can employ one or more solar collector members ofa type different from the solar collector fins 7 described above. Forexample, the invention can be practiced with flate-plate solar collectormembers used in the RITH (Roof Integrated Thermosiphon) TechnologyDevelopment program by Sandia National Laboratories, parabolic or othershaped solar collectors, and any other solar collector. Moreover, theskylight/solar fluid heating apparatus can be modified by using areduced number of more efficient solar collector fins that providegreater heat transference to the water or other working fluid and reducethe number of solar collector fins needed. This modification canincrease the distance between each solar collector fin 7 for example toprovide more interior lighting of the building.

Four skylight/solar fluid heating apparatus of the type described abovecan be used on a building to transmit about the same amount of light asone standard two by four foot skylight. Moreover, three to fourskylight/solar water heating apparatus of the type described above mayprovide 50-80% of the domestic hot water required for a household offour individuals depending upon the service conditions, such as angle ofincidence and geographic location of the apparatus.

FIG. 5 provides a schematic view of connector piping or conduits CC forinterconnecting rows of the fluid conduit sections 12 a of the solarcollector fins (not shown) of four adjacent skylight/solar water heatingunits A1, A2, A3, A4 in serial fluid flow manner according to anotherembodiment of the invention. In this embodiment, lengths of connectorpiping conduits CC interconnect in series fluid flow the rows of fluidconduit sections 12 a of adjacent units A1, A2, A3, A4 so that, forexample, the fluid conduit section 12 a of the bottom solar collectorfin of unit A1 is connected in series water flow relation to the fluidconduit section 12 a of the bottom solar collector of the next adjacentunit A2, the fluid conduit section 12 a of the bottom solar collectorfin of unit A2 is connected in series water flow relation to the fluidconduit section 12 a of the bottom solar collector of the next adjacentunit A3 and so on as represented by the arrows to provide a serial waterflow through all of the fluid conduit sections 12 a of the units A1through A4. U-shaped conduit sections 12 b are provided on the end unitsA1 and A4 to redirect the water flow as needed to achieve the overallserial flow through the fluid conduit sections 12 a of all of the unitsA1 through A4.

It is to be understood that the invention has been described withrespect to certain specific embodiments thereof for purposes ofillustration and not limitation. The present invention envisions thatmodifications, changes, and the like can be made therein withoutdeparting from the spirit and scope of the invention as set forth in thefollowing claims.

1. A skylight/solar fluid heating apparatus, comprising a housingadapted for mounting on a building, a light-transmitting outer cover onthe housing so that light can enter the housing, and a solar fluidheater disposed on the housing in a manner to absorb solar radiation forheating a working fluid and to allow some light to pass through thehousing into the building.
 2. The apparatus of claim 1 wherein the solarfluid heater includes a plurality of solar collector members arrangedrelative to one another or to the housing to define one or more openspaces for transmitting light into the building.
 3. The apparatus ofclaim 2 wherein the solar collector comprises a plurality of solarcollector fins extending across a first dimension of the housing andspaced apart from one another along a second dimension of the housing toprovide open spaces through which light can pass into the building. 4.The apparatus of claim 3 wherein each of the plurality of solarcollector fins includes a section of the fluid conduit.
 5. The apparatusof claim 4 wherein each section of the fluid conduit is connected to aU-shaped section of the fluid conduit that is supported on the housing.6. The apparatus of claim 3 further including thermal insulation on thesolar collector fins on a respective surface thereof facing toward theinside of the building.
 7. The apparatus of claim 1 wherein the solarfluid heater includes a solar collector member connected in heattransfer relation to a fluid conduit that is connected to a waterheater.
 8. The apparatus of claim 1 further comprising alight-transmitting glazing sheet disposed in the housing between theouter cover and the solar fluid heater.
 9. The apparatus of claim 8wherein the glazing sheet is tempered glass or polycarbonate.
 10. Theapparatus of claim 1 further including a movable shade in the housing,said shade being deployed to reduce the amount of light passing into thebuilding.
 11. Combination of a fluid heater and a plurality of theskylight/solar fluid heating apparatus of claim 1 disposed on a buildingin a manner to provide solar heated fluid to the fluid heater.
 12. Thecombination of claim 11 wherein the fluid heater comprises a waterheater and the skylight/solar fluid heating apparatus provides solarheated water to the water heater.
 13. The combination of claim 11wherein the skylight/solar fluid heating apparatus are interconnected byconnector piping to provide a serial fluid flow through fluid conduitsections thereof.
 14. A method of using solar energy, comprising thesteps of disposing a solar fluid heater on a housing that is mounted ona building such that light enters the housing, absorbing solar radiationentering the housing using the solar fluid heater for heating a workingfluid thereof, and transmitting some light entering the housing into thebuilding through one or more open spaces defined by solar collectormembers of the solar fluid heater and/or their relation with thehousing.
 15. The method of claim 14 including providing the solar fluidheater with a plurality of solar collector fins extending across a firstdimension of the housing and spaced apart from one another along asecond dimension of the housing to provide one or more open spacesthrough which light can pass into the building.
 16. The combination of aplurality of solar fluid heating apparatus, each solar fluid heatingapparatus comprising a solar fluid heater disposed to absorb solarradiation for heating a working fluid wherein the solar fluid heatercomprises a plurality of solar collectors each having a respective fluidconduit section, wherein the fluid conduit section of the solarcollector of the first of the plurality of the apparatus is fluidinterconnected to the fluid conduit section of the corresponding solarcollector of the next adjacent of the plurality of the apparatus and soon to provide a series fluid flow through the fluid conduit sections ofall of the solar collectors.